Patent GB-324906-A (GB)
Abstract: 324,906. Heyne, W. O., Packman, P. J., and Plessey Co., Ltd. Oct. 29, 1928. Totalizators.-The invention relates to totalizators of the type in which the indicators are operatively connected with the totalling apparatus by means including hunter gears, the master members of which are driven in unison with the totalling apparatus and the followers with the indicators. The invention consists in providing clutches in the drives to the followers of the hunter gears and means controlled by the hunter gears whereby the clutches are operated to make the said drives when the hunter gears are hunting and to break them when the gears are at rest. The totalling apparatus 1, 2, Fig. 1, may be of the electromagnetic escapement type described in Specification 287,767. The rotors of the escapements are continuously urged to rotate by a friction drive transmitted through a continuously rotating pulley 3. A shaft 4 rotates an amount which is the sum of the movements of the various escapement units. Secured to the shaft 4 is a bracket 13 in which is a pivoted latch 14 controlled by a spring 17 acting through a rod 16 slidable within the shaft 4. The bracket and latch from the master member of the hunter gear. Loosely mounted upon the shaft 4 is a cam disc 5 forming the follower of the hunter gear and having a depression 29. The latch 14 rides on the cam track. The disc 5 carries a spur wheel 7 gearing with a pinion 8 fixed to a shaft 9 connected through a one-revolution clutch 10 to a continuously-running power shaft 11. When the shaft 4 rotates one step the latch 14 moves out of the depression 29 (in which it normally lies) on to the cam track, thereby closing a switch 28 and energizing a magnet 27, which lifts a catch 24 to allow the engagement of the spring controlled idle half 22 of the clutch 10 with the continuously rotating part 21. This former half 22 has a cam lobe 25 which, after one revolution, will engage with the shaft 24 (if the latter is released bv the magnet 27) and will cause the disengagement, of the clutch. This occurs when the disc 5 overtakes the latch 14, and the latter re-enters the depression 29. The indicators, if remote, are operated by impulses caused by the closing either of a switch 18 by a roller 19 or of a series of switches, not shown, by a roller 20 on the disc 5. If the indicator dials are adjacent to the counters the follower disc 5 may be driven through the indicators as shown in Fig. 2, where a belt 51 drives both the pulley 53 urging the escapement rotors and also the pulley 12, and hence the indicator drum 47, through the clutch 10 and spur wheels 45, 46. The follower disc 5 is driven from the indicator drum by means of sprocket gearing 48, 49, 50. When the latch 14, Fig. 1, over-runs the cam disc 5, it contacts with a projection 34 on a member 30, which is revoluble on the shaft 4. This member is pushed to the right, and so guides the latch past the depression 29 in the disc 5, the movement continuing until the member meets a stop 32, when the latch is forced to ride up the projection 34 and so to close a switch 35a connected to one of the escapements controlling the indicator of the next higher order. The switch 35<a> also closes a circuit through a magnet 40, which moves an armature 41 and trip member 42 having a projection 43 which, when the latch 14 is riding up the projection 34, lies to the right of and engages a collar 44 on the rod 16. This releases the pressure of the latch on the projection 34, and allows the member 30 to move back to its normal position under spring action. The collar 44 is released from the trip member 42 by the latter becoming depressed by contacting with an inclined projection of the frame of the magnet 40. A decimal succession of indicators is employed. Each indicator may have its own series of escapements, in which case each indicator after the first has an escapement which receives an impulse whenever the next lower indicator completes one revolution. Alternatively, the higher dials of the series may be connected together by a cyclometer gearing. Specifications 312,977, [Class 106 (ii), Dynamometers &c.], 325,073; and 325,111, [Class 40 (i), Electric signalling systems &c.], also are referred to. The first Provisional Specification refers to Specification 286,997, and also describes an alternative method of transmitting the over-running impulses of the master member 14 by providing contacts on the master member 14 and on the cam member 5. In a modification, the disc 5 forms the master member and the bracket and latch 14 the follower of the hunter gear. Reference has been directed by the Comptroller to Specification 321,154.